An instant success since the first book in 1971, the series remains amazingly popular worldwide. Now in their 40th year, Mr Men books have sold more than 100 million copies in 28 countries. The series now includes 44 Mr Men and Little Misses.

Hargreaves reportedly started his career as an author and illustrator when his son asked him what a tickle looked like, which resulted in his first character (and firm Crave favourite), Mr Tickle. We love Mr Bump too. Hargreaves died in 1988, and in 2004, his family sold the rights to Mr Men and Little Miss to Chrion for a cheerful £24m.

With four animated TV series, Hargreaves' stories got the feature-length treatment in 2010, with Twentieth Century Fox creating Mr Men: The Movie. We haven't seen it, but we imagine it's like X-Men, but with more tickling. Who's your favourite Mr Man?